Arc tube mount



Jan. 31, 1956 P. A. DELL ARC TUBE MOUNT Filed Supt. 12'. 1951 Inventor- Paul A. D by/ ell, a 4

-52. rney.

His Atto 2,733,363 Patented Jan. 31, 1956 2,733,363 ARC TUBE MOUNT Paul A. Dell, Highland Heights, Ohio, assignor to General Electric Company, a corporation of New York Application September 12, .1951, Serial No. 246,231 '5 Claims. (Cl- 31327) The present invention relates to high pressure electric discharge lamps having an inner are tube of vitreous material, an outer vitreous envelope and a mount supporting saidtube in said envelope.

Heretofore such lamps have been made with beaded inlead wires extending from rounded or tapered ends of the arc tube and the support for the arc tube has engaged the hot tube inwardly from the 'inleads. Such structure, due to the high operating temperature of the arc tube, has presented 'difliculties in supporting the tube without conducting too much heat away from it through the supports, in avoiding electrolysis of the vitreous tube material by the electrically charged support members engaging the tube, .and in avoiding thermal shock of sufiicient magnitude to cause cracking of the tube.

Recently vitreous arc tubes having an externally extending pinched seal at each end of the tube have been made commercially available by the assignee of the present application and the principal object .of the present inscription of species thereof and from the appended claims.

In the drawing accompanying and'forming part of this specification species of the invention are shown in which, Fig. l is a perspective view of a discharge lamp of the high pressure type in which the mount for the iner arc tube engaging member of the mount shown in Fig. 1; Fig. 3 is a similar view of another species of arc tube engaging member embodying the invention, and Fig. 4 is a similar view of still another are tube engaging member embodying the invention.

Referring to Fig. l of the drawing the lamp comprises an outer vitreous envelope 1 having a re-entrant stem 2 through the pinch 3 of which extend the leading-in wires 4 and 5 which are connected at their outer ends to the contacts on the usual screw type base 6 of the lamp and terminate within the outer envelope for connection tov the terminals of the inner arc tube 7.

The inner arc tube 7 is made of hard vitreous material, such as quartz, and has sealed therein at opposite ends thereof a pair of main discharge supporting electrodes 8 and 9 the inleads 11 and 12 of which constitute the arc tube terminals. An auxiliary starting electrode is sealed into one end of the tube 7 adjacent the main electrode 8. The current inlead wires 11, 12 and 13 for said electrodes 8, 9 and 10, respectively, have a thin flattened section hermetically united with the pinched end tube portions 14 and 15 extending outwardly from the arc tube 7 as described and claimed in my copending joint application with Edward B. Noel, Serial No. 244,818, :filed September 1, 1-951, titled Ribbon Lead Construction, now Patent No. 2,667,595, patented January 26, 1954, and assigned to the assignee of this application. The are tube 7 has a fillingof starting-gas,

ating temperatureof the arc tube 7. a

The mount for the arc tube 7 within the outer envelope 1 comprises a harness made up of aU-shaped stiit metal wire having its bent center portion 16 welded to the inlead 4 of stem 2 and its parallel legs 17 and 18 extending longitudinally of the arc tube 7 and terminating at the opposite end of the outer envelope 1. A pair of spring members 19 and 20 press against the enve'lope'l and are welded to the free ends of the legs 17 and '18, respectively, and a spreader member 21' tached to and bet-ween the free ends of the The U-shapedsupport is thus firmly held the envelope 1. 1

The are tube 7 is attached to the U-shaped support by transverse metal channel members 22 and 23 weldedto the legs 17 and 18 of the U-shaped support and engaging the outer ends of the pinched portions 14 and 15 of the tube '7. The channel supports 22 and 23 are of the same structure and are provided with tabs 24 (Fig. 2) bent inwardly into the channel and welded to the legs 17 and '18 of the wire support. The central portion or 'web of each of the channel-supports 22 and 23 is cut and shaped to provide an elongated opening for receiving a fiat pinch in position in 25 and 26. The fingers 25 and '26 corners ofthe pinch parts '14 and 15 of the arc tube '7, as best shown in Fig. 2, in which pinch part 14 and the shown in'broken lines. The channel supports 22 and 23 are so spaced on the legs .17 and 18 of the U-shaped support that the arc tube "7 is held firmly therebetween.

and pointed out above are thus completely avoided by the different structure of the present mount.

In the embodiment of Fig. 4 of the drawing the fingers 30 and 31 are bent ilarly notched portions of the press 14.

The electrical connections between the electrodes 8, 9

pair of rounded resilient fingersv engage the outer and 10 and the current inleads 4 and 5 connected with contacts on the base 6 of the lamp shown in Fig. l are made in the conventional manner. Main electrode 9 is connected through its inlead 12 and theflexible conductor 35 to the leg 17 of the U-shaped mount, the center portion 16 of which is welded to the inner end of current lead 4. The main electrode 8 is connected through its inlead 11 and a flexible conductor 36 to the inlead 5. The said conductor 36 passes through an opening in the metal heat shield 37 secured to the legs 17 and 18 of the U-shaped mount and is electrically insulated from said shield by the glass tube 38. The auxiliary electrode 10 is electrically connected to the main electrode 9 through its inlead.13, the flexible conductor 39, the resistor 40 and the stiff conductor 41 welded to the portion 16 of the U-shaped support member. The flexible conductor 39 also passes through the opening in the heat shield 27 and is electrically insulated from said shield by the glass tube 42.

What I claim as new and desire to secure by Letters '2.

Patent of the United States is:

1. An electric discharge lamp of the high pressure type comprising in combination, a vitreous arc tube having at each end an external flat press portion carrying an electric terminal, an outer envelope enclosing said arc tube, and a mount supporting said tube in fixed position within said envelope, said mount comprising a U-shaped stiff metal wire support attached to said envelope and narrow, spaced transverse metal members attached to the legs of said support and supporting said are tube therebetween, each of said narrow transverse members having an elongated central opening accommodating a press portion of said are tube with the sides of said opening engaging said press portion to limit lateral movement of said are tube in said envelope, each of said transverse support members comprising also integral spring fingers extending from the ends of said opening into engagement with the said accommodated press portion, the said fingers on said transverse support members resiliently holding said arc tube against longitudinal displacements in said envelope and with the tubular portion of said are tube spaced from said transverse support members to minimize heat losses from said are tube through said mount.

2. An electric discharge lamp of the high pressure type comprising in combination, a vitreous arc tube having at 4 each end an external flat press portion carrying an electric terminal, an outer envelope enclosing said arc tube, and a mount supporting said tube in fixed position within said envelope, said mount comprising a U-shaped stifl metal wire support and narrow, spaced transverse metal members attached to the legs of said support and supporting said are tube therebetween, each of said transverse support members being shaped as a channel having upstanding sides spacedapart a distance slightly greater than the thickness of the flat press portions of the arc tube and having an elongated central opening in its web accommodating a press portion of said tube the sides of which engage the said press portion to limit lateral displacements of said tube in said envelope, each of said transverse support, members having also integral spring fingers extending from the ends of said opening into engagement with the said accommodated press portion, the said fingers on said transverse support members resiliently holding said are tube against longitudinal displacements in said envelope and with the tubular portion of said are tube spaced from said transverse support members to minimize heat losses from said are tube through said mount.

3. An electric discharge lamp as in claim 2 wherein the spring fingers are bent inward into the channel-shaped member and engage the corners of said press.

4. An electric discharge lamp as in claim 2 wherein the spring fingers are bent inward into the channel-shaped member and are provided with openings so as to hook over the corners of said press.

5. An electric discharge lamp as in claim 2 wherein the spring fingers are bent outward and engage the sides of said press.

References Cited in the file of this patent UNITED STATES PATENTS 2,009,211 St. Louis July 23, 1935 2,056,926 Krefit Oct. 6, 1936 2,175,361 Reger Oct. 10, 1939 2,177,712 Jenkins Oct. 31, 1939 2,240,333 Hodge Apr. 29, 1941 2,286,789 Dench June 16, 1942 2,491,868 Martt Dec. 20, 1949 2,562,887 Beese Aug. 7, 1951 FOREIGN PATENTS Australia May 31, 1940 

